Get Started (C#)

Table of contents

Introduction
Prerequisites
Creating your project
Setting up the basics
Trying your app out
Surprise ending

Introduction

For an overview of what Alloverse and alloapps are, please see the first chapters of the Get Started (Lua) guide.

Note that Lua is the preferred alloapp language, and C# language support is in beta.

Prerequisites

To write Alloverse apps in C#, you’ll need the following:

The Alloverse app.
Either Visual Studio Community >= 2019 (on a Mac or Windows machine)…
Or a plain text editor for code (We recommend Visual Studio Code), together with a command line terminal.

Personally, I’m more of a Linux/Mac with command line kind of person, so this guide will primarily be using the dotnet. I’ll try to include the equivalent Visual Studio screenshots so that you can follow along without using a Terminal.

Creating your project

Let’s create a new C# project:

$ dotnet new console -n fancyapp
$ cd fancyapp

Add AlloUI as a dependency:

$ dotnet add package AlloUI

You remember how I said at the top that this is a beta? There’s one really terrible hack you’ll have to do until I figure out how to properly package native code in a nuget package.

You have to manually download liballonet.so, and put it at /home/nevyn/Dev/allonet/build/liballonet.so. This unfortunately means that this’ll only work on Linux for now.

$ mkdir -p /home/nevyn/Dev/allonet/build/
$ curl -o /home/nevyn/Dev/allonet/build/liballonet.so https://alloverse-downloads-prod.s3.eu-north-1.amazonaws.com/allonet/3.0.63.g131e106/liballonet.so

Setting up the basics

Open up Program.cs. The most basic setup for an alloapp is one which:

Creates an AlloClient and connects to the specified alloplace server,
and creates some basic UI elements,
and starts the runloop which will serve requests.

Modify your file to look something like this, adjusting to taste;

using System;
using System.Diagnostics;
using System.IO;
using System.Collections;
using System.Collections.Generic;
using AlloUI;

namespace fancyapp {
    class Program
    {
        // AlloUI.App manages your connection to the place
        App app;
        static void Main(string[] args)
        {
            Program sample = new Program();
            // Let's use the first commandline argument as the place's URL
            sample.Run(args[0]);
        }

        void Run(string url)
        {
            // This is step 1.
            // Create a client and an app which manages the connection for us.
            app = new App(new AlloClient(), "fancyapp");
            // Step 2 is to create our UI
            app.mainView = MakeMainUI();
            // Step 3: connect and run. Run never returns until program
            // is stopped.
            app.Connect(url);
            app.Run(20);
        }

        View MakeMainUI()
        {
            // Simple UI with a cube and a button
            Cube cube = new Cube{
                Bounds= new Bounds{
                    Size= new Size(1.0, 1.0, 0.10)
                }.Move(0, 1.5, -2),
                Color= new Color(0.9, 0.7, 0.9, 1)
            };
            // Button is laid on top of cube
            Button button = cube.addSubview(new Button{
                Bounds= new Bounds {
                    Size= new Size(0.6, 0.13, 0.1)
                }.Move(0, 0, cube.Bounds.Size.Depth/2.0 + 0.05),
            });
            button.Label.Text = "Do the thing";
            // handle clicking the button
            button.Action += delegate(object sender, Button.ActionArgs args) {
                Console.WriteLine("Hello world!");
            };
            button.Cube.Color = new Color(1,1,1,1);

            // make the cube moveable
            cube.IsGrabbable = true;
            return cube;
        }
    }
}

Trying your app out

That’s it! You should now be able to start your project and see it appear in an Alloplace. If you don’t have one already, you can use our sandbox alloplace://sandbox.places.alloverse.com, or be ambitious and boot one on your own (docker run -e ALLOPLACE_NAME="my place" -p 21337:21337/udp -it alloverse/alloplace2). I’m gonna do the former:

$ dotnet run alloplace://sandbox.places.alloverse.com

If it all checks out, you should be able to jump into that place on your VR headset or computer and press the button it has created.

Download the Visor app for your VR or desktop platform of choice, and then click “Connect”, “Sandbox” (or click the alloplace link of the place you’ve rented or started yourself).

On the left, the UI of our app shown as a white rectangle with an orange button. On the left, a terminal showing the assist run command that instantiates the app; and the word Hello printed thrice. Our app running in Sandbox place. I’ve clicked our simple app’s white button button three times, and the laws of causality held up, printing “Hello” thrice to our terminal.

At this point, you could go off, do your own thing, read the documentation as you go. Or you could keep reading, and be guided through the development of a simple but functional todo list app, which will help establish the fundamentals and make it much easier for you to build real, complex apps.

This is also a good point at which to remind you: if you get stuck, or have questions or feedback, please hop on Discord and give it to us straight.

Surprise ending

This is where one would expect the tutorial to really get started, teaching the deeper concepts and doing something more advanced. But alas, the number of hours in a day are finite, and the docs are left unwritten.

Maybe see it as a challenge? “Left as an exercise to the reader” and all that. Who knows, maybe you end up sending us a docs improvement PR? ;)

And again, if you have any questions, hop on Discord!